The mixing of substances, such as different types of solids, liquids and/or gases has a number of applications in different industries. For example, in the pharmaceutical industry, different types of drugs are mixed together. In the medical field, body fluids (such as blood) and/or drugs are typical substances that are mixed. The agricultural industry also incorporates mixing operations into a number of applications. For example, water is mixed with dehydrated food for the rehydration of such food.
However, in these and other industries, the substances that are mixed may be hazardous, dangerous and/or infectious. For example, in the pharmaceutical and/or medical industries, the substances that are to be mixed may be toxic. Additionally, in a number of situations, the handling of powders may be dangerous because of the possibilities of inhalation of such powders. Furthermore, in the medical field, individuals that handle body fluids, such as fluids that are HIV-infected, do so without attempting direct contact of these fluids.
Conventional mixing devices generally involve a glass tank for substances that are of small volumes and a stainless steel tank for substances of larger volumes. These tanks often include a screw to agitate and maintain powders within suspension. Such screws are also used to homogenize multiphase solutions. Prior to use, these mixing tanks must be washed and sterilized. Typically, an autoclave is used for washing and sterilizing small volume tanks, while a water steam-based operation is employed for washing and sterilizing larger volume tanks. These wash and sterilize operations, which are essential to mixing when using such devices, are typically time consuming, expensive and require highly qualified individuals. Further, periodic maintenance of these mixing devices must be performed to ensure proper operation. In certain cases, such washing/sterilizing operations as well as the maintenance of these mixing devices may represent more than a third of the total cost of the mixing devices and maintaining thereof, which may be prohibitive for given applications. Additionally, mixing of substances may cause the pressure to increase within these conventional mixing devices. If this increased pressure is not accounted for, the mixing of such substances may become dangerous, wherein the tanks could break apart/explode due to this internal pressure. Moreover, with the use of many mixing devices currently employed to mix pharmaceuticals, one cannot be certain whether any such pharmaceutical has been displaced outside the mixing device and therefore the amount of pharmaceutical remaining inside the mixing device, after mixing, may not be sufficiently accurate or precise. This is problematic when the FDA requires the administration of such a pharmaceutical in precise, accurate and known quantities.